The biggest shift in LEED v4 is its call for disclosure of the content in various building materials to limit exposure to "chemicals of concern" that may affect health. The new standards are "moving away from single-attribute thinking for materials selection towards an approach that considers life-cycle impacts and health impacts of material ingredients," says Mella.
With the new emphasis on building material content, designers no longer can focus solely on designing a building, but also must consider the contents of a structure for the long run. LEED v4 and the Living Building Challenge "are exerting more pressure on the community by incorporating holistic and comprehensive material requirements that are more heavily weighted within their systems," says Powell.
Some building materials trade associations have vigorously opposed disclosure and have suggested that simply asking for an accounting of material ingredients exposes designers to unprecedented liability. "This position has been rejected by in-house legal counsel for many of the largest firms and, in fact, we are now three years in and the sky hasn’t fallen yet," says Perry of SmithGroupJJR.
While many designers are looking at the broad issues raised by sustainable design, clients and government agencies are looking for very tangible benefits from green design. "There continues to be an increasing focus on actual performance outcomes, on achieving the results promised during design, in particular with regards energy performance," says Marseille of WSP/Parsons Brinckerhoff.
Marseille says this focus is starting to show up more in public project design/build contracts, is a requirement of compliance with some green building certifications, and even is starting to show up in building codes. "This new increased level of accountability is driving more integrated partnerships by those being held to account—architects, engineers, contractors, and building owners, operators and occupants," he says.
Seeking Tangible Benefits
However, Marseille cautions against taking the easy way out for results. He cites results from the continuing reduction in construction costs for photovoltaics and their low relative maintenance requirements. The low cost/low maintenance option "represents an increasing trend toward offsetting building energy usage using PV rather than prioritizing reducing building energy demand," he says. This "myopic focus on energy efficiency through investment in PV is not necessarily compatible with the delivery of the highest building indoor environmental quality," he says.
Part of the demand for tangible benefits for sustainable building can be seen on the West Coast and the Southwest, where there is an increased interest in water reuse systems. In drought-stricken California, some jurisdictions are encouraging and/or requiring projects of a certain size to incorporate water reuse systems.